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Koleken

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Koleken
Temporal range:
Maastrichtian, ~71.7 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Abelisauridae
Subfamily: Carnotaurinae
Clade: Brachyrostra
Clade: Furileusauria
Tribe: Carnotaurini
Genus: Koleken
Species:
K. inakayali
Binomial name
Koleken inakayali
Pol et al., 2024

Koleken (meaning "coming from clay and water") is a genus of carnotaurin abelisaurid from the Maastrichtian La Colonia Formation in the Chubut Province of Argentina. The type and only species is K. inakayali, known from one immature specimen about six years old in minimum age.[1]

Discovery and naming[edit]

Koleken is known from only the holotype MPEF-PV 10826 which was initially found and reported in 2015,[2] but was not described as K. inakayali until 2024. The holotype, consists of "closely associated (but disarticulated) remains of the skull and atlas, as well as the articulated postcranial skeleton composed of the posterior most eight dorsal vertebrae, a complete sacrum, eight caudal vertebrae, an almost complete pelvis and hind limbs". It differs from the larger Carnotaurus in anatomical characteristics found in the skull, vertebrae, and leg bones. The specimen likewise is believed to represent a sub-adult based on a lack of fusion in some of the bones.[1]

The generic name, Koleken (IPA: [kɒːlɛkɛn]), is a name in Teushen spoken by the native population of central Patagonia that means "coming from clay and water", given the specimen was found in a sedimentary section dominated by claystone representing an estuarine environment. The specific name, inakayali (IPA: [ɪnækæjælaɪ]), honours Inakayal, one of the last chiefs of Tehuelches, native people from central Patagonia.[1]

Classification[edit]

Koleken is placed in the Carnotaurini tribe of Abelisauridae, in a polytomy with the other carnotaurins in a phylogenetic analysis:[1]

Abelisauridae

Paleoenvironment[edit]

Koleken was found in outcrops of the La Colonia Formation, which dates to the Maastrichtian (Cretaceous)–Paleocene (Paleogene) boundary.[3] This formation is best known for fossils of the abelisaurid theropod Carnotaurus and the saltasauroid titanosaur Titanomachya,[1][4] as well as fossils of other reptiles including the turtle Patagoniaemys, the snake Alamitophis and the plesiosaurs Kawanectes, Chubutinectes and Sulcusuchus.[2][5][6][7] Mammals discovered from the formation include Reigitherium, Coloniatherium, Argentodites and Ferugliotherium.[8][9] Remains of an enantiornithine and, possibly, of a neornithine bird have been discovered.[10][11]

References[edit]

  1. ^ a b c d e Pol, Diego; Baiano, Mattia Antonio; Černý, David; Novas, Fernando; Cerda, Ignacio A.; Pittman, Michael (21 May 2024). "A new abelisaurid dinosaur from the end Cretaceous of Patagonia and evolutionary rates among the Ceratosauria". Cladistics. doi:10.1111/cla.12583.
  2. ^ a b Gasparini, Zulma; Sterli, Juliana; Parras, Ana; Patricio O'Gorman, José; Salgado, Leonardo; Varela, Julio; Pol, Diego (May 2015). "Late Cretaceous reptilian biota of the La Colonia Formation, central Patagonia, Argentina: Occurrences, preservation and paleoenvironments". Cretaceous Research. 54: 154–168. Bibcode:2015CrRes..54..154G. doi:10.1016/j.cretres.2014.11.010. hdl:11336/19244. Retrieved 21 May 2024.
  3. ^ Clyde, W. C.; Krause, J. M.; De Benedetti, F.; Ramezani, J.; Cúneo, N. R.; Gandolfo, M. A.; Haber, P.; Whelan, C.; Smith, T. (1 October 2021). "New South American record of the Cretaceous–Paleogene boundary interval (La Colonia Formation, Patagonia, Argentina)". Cretaceous Research. 126: 104889. Bibcode:2021CrRes.12604889C. doi:10.1016/j.cretres.2021.104889. ISSN 0195-6671.
  4. ^ Pérez-Moreno, A.; Salgado, L.; Carballido, J. L.; Otero, A.; Pol, D. (2024). "A new titanosaur from the La Colonia Formation (Campanian-Maastrichtian), Chubut Province, Argentina". Historical Biology: An International Journal of Paleobiology: 1–20. doi:10.1080/08912963.2024.2332997.
  5. ^ O’Gorman, José P.; Carignano, Ana Paula; Calvo-Marcilese, Lydia; Pérez Panera, Juan Pablo (10 August 2023). "A new elasmosaurid (Sauropterygia, Plesiosauria) from the upper levels of the La Colonia Formation (upper Maastrichtian), Chubut Province, Argentina". Cretaceous Research. 152: 105674. Bibcode:2023CrRes.15205674O. doi:10.1016/j.cretres.2023.105674. ISSN 0195-6671.
  6. ^ José Patricio O'Gorman (2020). "First record of Kawanectes lafquenianum (Plesiosauria, Elasmosauridae) from the La Colonia Formation of Argentina, with comments on the mandibular morphology of elasmosaurids". Alcheringa: An Australasian Journal of Palaeontology. 44 (1): 176–193. Bibcode:2020Alch...44..176P. doi:10.1080/03115518.2019.1687754. S2CID 213090343.
  7. ^ O'Gorman, J.P.; Gasparini, Z. (2013). "Revision of Sulcusuchus erraini (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina". Alcheringa: An Australasian Journal of Palaeontology. 37 (2): 163–176. Bibcode:2013Alch...37..163O. doi:10.1080/03115518.2013.736788. hdl:11336/2489. S2CID 131429825.
  8. ^ Forasiepi, Analía M.; Coria, Rodolfo A.; Hurum, Jørn; Currie, Philip J. (1 December 2012). "First Dryolestoid (Mammalia, Dryolestoidea, Meridiolestida) from the Coniacian of Patagonia and New Evidence on their Early Radiation in South America". Ameghiniana. 49 (4): 497. doi:10.5710/AMGH.8.8.2012.581. S2CID 129208347.
  9. ^ Gurovich, Y.; Beck, R. (2009). "The phylogenetic affinities of the enigmatic mammalian clade Gondwanatheria". Journal of Mammalian Evolution. 16 (1): 25–49. doi:10.1007/s10914-008-9097-3. S2CID 42799370.
  10. ^ Lawver, Daniel R.; Debee, Aj M.; Clarke, Julia A.; Rougier, Guillermo W. (1 January 2011). "A New Enantiornithine Bird from the Upper Cretaceous La Colonia Formation of Patagonia, Argentina". Annals of Carnegie Museum. 80 (1): 35–42. doi:10.2992/007.080.0104. S2CID 85015365.
  11. ^ Acosta Hospitaleche, C.; O'Gorman, J. P.; Panzeri, K. M. (2023). "A new Cretaceous bird from the Maastrichtian La Colonia Formation (Patagonia, Argentina)". Cretaceous Research. 150. 105595. Bibcode:2023CrRes.15005595A. doi:10.1016/j.cretres.2023.105595. S2CID 259059084.